Articles of reinforced foam material



Aug. 1, 1961 c. L. OTTO ET AI. 2,994,327

ARTICLES OF REINFORCED FOAM MATERIAL Filed April 26, 1955 II "II [HIM fda zZ M ATTORNEY 26, 1955, Ser. No. 503,861 Claims.

The present invention relates to articles of reinforced foam materialand to the manufacture thereof, and has particular reference to sucharticles in which the foam material is of resiliently elastic nature,while the reinforcement is provided by stiffer material.

By way of example, but without limitation, articles to which theinvention is particularly applicable are the core members, usuallycylindrical, of hair curlers around which strands of hair to be curledare wound and then clamped in place by retaining members engaging thestrands of hair and the core member.

For such articles to be satisfactory they must be light, elasticallyresilient, and should be porous to the extent required to afford thesubstantial degree of ventilation required to secure the relativelyrapid drying of hair wound thereon that is desirable. Additionally, thearticles, to have practical commercial acceptance and value, must berelatively very cheap.

From the standpoint of the above mentioned physical characteristics,foam material of various synthetic resins such as various vinylderivatives and other polymers such as polyesters and polyurethanederived from isocyanate, also various forms of foam rubber both naturaland synthetic, all of which materials may be generically termed plasticfoam, satisfy the requirements, but such materials do not have therequisite physical strength in resistance to bending to provide theaxial stiffness necessary for a satisfactory core member of a haircurler or similar devices requiring a certain minimum degree oflongitudinal structural strength. Accordingly the present inventioncontemplates to provision of a new article of the character describedcomprised of an elongated circumferential continuous hollow body ofresiliently elastic foam material longitudinally stiffened by a centralhollow reinforcing element of other more dense and structurally stiffermaterial, preferably relatively light and non-frangible syntheticplastic material, which liner is advantageously in the form of acylindrical tube but which may be in the form of a solid core.Preferably, both the body and the reinforcing element are tubular. Forthe intended purpose, numerous of the known synthetic thermoplasticmaterials may be employed, polyethylene being noted by way of examplebut without limitation, as a suitable material of that class.

As will be observed from the drawings, the invention contemplates theprovision of a core member formed by a body of foam material ofrelatively large diameter, particularly as compared with the diameter ofthe internal reinforcing element, and said body provides what is ineffect a soft pillow of foam material of bolster-like form upon whichthe hair is to be wound, the bolster-like body being highly compressibleunder the tension applied by winding the hair thereon, so that it mayreadily be manipulated by the user to Wind coils of different diameter,depending upon the tension applied. Also, the high degree ofcompressibility of the body insures the maintenance of the desiredtension on the hair that has been wound, even though after winding thehair, some slippage of the hair on the coil member may occur because offailure of the clip or other fastening means to hold the hair againstany movement relative to the supporting body. Such advantageousfunctions can as a practical atent ice matter be attained only when, asnoted, the body of foam material is of relatively large diameter ascompared with the central reinforcing element which is substantiallyincompressible.

Core members embodying the structure herein disclosed have been sold andused and are now being sold and used in commercial production quantitiesand it has been found that in order to secure the beneficial resultsthat are presently to be obtained the outer diameter of the body of foammaterial should be at least twice that of the relatively stiff andincompressible reinforcing element, and preferably should be at leastthree or more times the diameter of the reinforcing element, so that thewall thickness of the foam pillow will be at least as great as thediameter of the reinforcing element, as illustrated in FIG. 3.

As previously noted, an important requirement for articles of the kindunder consideration is low cost, and accordingly in another of itsaspects the invention contemplates the production of such articles bymethods and means resulting in a continuous compound extrusion processby virtue of which low costs are achieved through high rates ofproduction with relatively simple apparatus and from substantiallyentire elimination of waste of the component materials.

For a better understanding of the nature Of the inven tion and themanner in which it may advantageously be carried into effect, referencemay best be had to the ensuing portion of this specification in whichsuitable apparatus and operation thereof for producing articlesembodying the inventionare described in conjunction with theaccompanying drawings in which:

FIG. 1 is a fragmentary sectional view of extrusion apparatus forproducing the desired article.

FIG. 2 is a fragmentary vertical sectional view of extrusion apparatusfor producing the desired article and FIG. 3 is a perspective view of acore member for a hair curler or the like formed by a length of thearticle as extruded from the apparatus shown in FIGS. 1 and 2.

Referring now more particularly to the figures, 10 indicates generally acompound extrusion apparatus embodying a first extruder indicatedgenerally at A and a second extruder indicated generally at B. Thespecific forms of the extruders may be of any desired known type and byway of diagrammatic illustration, extruder A is shown as being providedwith a feed screw 12 for feeding liner material such as polyethylenearound the mandrel 14 so as to extrude an annular tube 16 of relativelythin wall section around the mandrel, the tube progressing into thechamber of the extruder B to which latter chamber foam material is fedby means of the feed screw 18. By way of illustration, FIG. 2 shows foammaterial, produced in the foaming machine diagrammatically illustratedat 20 and fed by means of the feed screw 22 to the feed screw 18 of theextruder B. The feed screws advantageously may be synchronized by meansof gears 24 connecting the drive shaft of the screw 22 with the powerinput shaft 26 constituting the drive shaft for the extruder B. The feedscrews 12 and 18 may also be interconnected so that a common source ofpower may be utilized to drive the entire apparatus.

As will be evident from FIG. 1, the foam material will be extruded inthe form of a sheath 28 around the liner 16 and with the foams ofpolymers such as those enumerated above, which have a relatively shortsetting time, further treatment following the discharge from extruder Bis ordinarily not required. With some materials, a certain amount ofcuring following extrusion of the foam material may be required, but thespecific procedures to be followed will be dictated by the particularmaterial employed, such specific procedures being generally known in theart.

For making articles such as cores for hair curlers and similar articles,frictional contact between the foam material and the liner is sutlicientto hold alone the components against relative axial displacement and forthe purpose of making such articles the only step required after theextrusion is ordinarily to cut the extruded material to desired lengthto produce an article of the kind desired, such as the core for a haircurler indicated generally at 30 in FIG. 3.

As previously noted, the core member such as is shown in FIG. 3, mayhave an annular liner or a solid liner or core, and either form mayadvantageously be used in conjunction With retaining members of the kindembodied in the disclosure of U.S. application Serial No. 456,485, filedSeptember 16, 1954, in the names of Carl L. Otto and La Nelle BurnhamOtto, now US. Patent No. 2,842,- 140 granted July 8, 1958.

While for purposes of disclosing the invention various examples havebeen given by Way of illustration, it will be understood that theinvention is not to be considered as limited to such examples, but is tobe considered as embracing all products falling within the scope of theappended claims.

What is claimed:

1. A core member for a hair curler comprising an elongatedcircumferentially continuous hollow body of highly compressibleelastically resilient foam material and a central hollow reinforcingelement of elastically yieldable non-metallic material substantiallystiffer than said foam material extending through said body, saidreinforcing element being open at both of its ends, said element andsaid body being substantially coextensive longitudinally and thediameter of said body of foam material being at least a plurality oftimes the diameter of said reinforcing element, whereby to provide asoft pillow of foam material of bolster-like form the outercircumference of which may easily be materially reduced by the windingof a tress of hair thereon under desired tension to thereby permit coilsof hair of difierent diameters to be formed on like core members asdesired by the user in accordance with the tension under which the hairis Wound and to insure maintenance of the desired tension of the hairWhile coiled on said member.

2. An article as defined in claim 1, in which both the body of foammaterial and the central reinforcing element are tubular in form, andthe radial thickness of the wall of said body of foam material is atleast as great as the outer diameter of said reinforcing element.

3. An article as defined in claim 1, in which said body of foam materialconsists of a synthetic polymeric resin.

4. An article as defined in claim 3, in which said central reinforcingelement consists of a synthetic thermo plastic material.

5. An article as defined in claim 3, in which said body of foam materialis of polyurethane.

6. An article as defined in claim 5, in which said central reinforcingelement is of polyethylene.

References Cited in the file of this patent UNITED STATES PATENTS1,726,359 Martell et al Aug. 27, 1929 1,751,844 Schanz Mar. 25, 19301,919,600 Seward July 25, 1933 1,974,924 MacDonald Sept. 25, 19342,061,817 Van Cleef Nov. 24, 1936 2,526,311 Wilson Oct. 17, 19602,594,348 Rockofi Apr. 29, 1952 2,600,727 Berman et al June 17, 19522,602,783 Simon et al. July 8, 1952 2,690,769 Brown Oct. 5, 19542,747,585 Allen May 29, 1956 2,759,475 Swaay Aug. 21, 1956 FOREIGNPATENTS 716,422 Great Britain Oct. 6, 1954 OTHER REFERENCES GermanPlastics Practice, copyright 1946 by Debell and Richardson, pp. 463-465.

